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[Plastic - RIP]

I don't really see any technical problems with record attempts these days - there are so many electrically powered bikes, golf carts, skateboards, etc that can supply reliable & cheap running gear for the boat - whatever the size.

In my opinion, everything else is straight forward - a big, sleek fibreglass hull to take the sufficient batteries & boyancy and weather/waterproofing for the internals, filled with foam so it's unsinkable, lots of bulkheads & bilge pumps etc.

The propshaft is the only real unknown - it's going to be running fast for long periods so lubrication / bearing failure and vibration will kill the attempt.

[John W E]

I am afraid there are a lot of problems that are unforeseen to overcome before we can get the biggest amperage battery to power the lowest amp motor in a model.  Originally, in the Leeds Castle she had 2 x 12 volt low drain similar to the Component Shop's 555 mounted on an Olympus (MFA) 2.5 : 1 belt drive gear box swinging a 45mm x 4 blade brass prop.    In the test tank, each motor was only drawing just under 1 amp on the meter.  This was okay - we set the test tank up in the garage and prepared to run it over 24 hours to see if the model would make it, using 3 x 12 volt x 14 amp buggy batteries.

Admittedly the weight of the batteries took the model above the waterline mark.  The receiver also run off a separate set of batteries; along with a body pack strapped to the transmitter and left to run.   After say about 15 hours - one of the motors had died - for no particular reason, plus, the stern tube had began leaking and the motors were retested and it was found that they were drawing slightly more than one amp.

We then replaced the motors and water-cooled them, along with a fan sucking air and cooling down the electrics inside the hull - because this had been noted as a problem.    This will give you an insight into some of the problems you have to overcome.

john

[Plastic - RIP]

The problems you list appear just to be basic engineering issues - do people think of the vehicle as a big model boat with cheap model boat parts or is it a small commercial speedboat with remote control?

I would suggest that model components are not engineered for continuous use - a couple of hours max and, reading these forums, people seem to have loads of grief with leaks, overheating, dodgy couplings etc. when using model-rated parts

Engineering downwards from commercial heavy duty may be a better choice.

[Arrow5]

Agree about the music.  At 1:28 there is a single frame shot of a Thames River Police launch a la the Veron kit.

[John W E]

Hi there plastic just to help suss things about The Leeds Castle - she was engineered to the highest standards - phosphor bronze bearings had been replaced with ball races and so forth.   Its not just a case of poor engineering.

http://www.modelboatmayhem.co.uk/forum/index.php/topic,28576.0.html

John

[Allnightin]

24 hour running is challenging for most standard RC gear.  My first attempt at the record ended when the gear couplings slipped and the reversing contacts on the ESCs (a very reputable brand) welded at forwards only after about 4 hours running.  I had to use roll pins for the gears and devise a resistance network with microswitches to have reliable speed control.

[Plastic - RIP]

I don't see electrical components being a problem - you just need to massively over-spec so they don't know they are doing any real work.

The couplings and propshafts will be the weak link due to half in water, half in the air lubrication issues and vibration problems gradually damaging the components until they fail.

That is why I suggest using commercial boat parts or custom made extra-heavy duty components.  I've never seen a 'model' boat propshaft that I would risk in any kind of record attempt.

Also, the UJ couplings always suffer from 'cogging' (which is why CV joints replaced them in cars) - if alignment is not perfectly straight, there will be built-in vibration from this compounded by the number of blades of the prop beating against the bottom of the boat.
 
Over time, it will damage lightweight hardware.

[John W E]

hi on paper the 24 hour race sounds simple but those in the know who have actually tried it, realise its not.   The models themselves work perfectly on the bench and some faults come to the fore on the test tank - but - the other thing is, and, something nobody has mentioned yet - is you have to organise a team.  They have to be well oiled to know whats happening and what to do - plus supplies etc.

john

[Stavros]

If I am right in thinking Andy Models by Design rewrote the record books a couple of years ago using one of his Boats

Dave

[Tid 65]

How about one set of batteries rated at 12v,80amps and a motor that draws 2-3 amps = 26-40 hours running time,just need to work out the speed to get a decent distance.

[John W E]

How about one set of batteries rated at 12v,80amps and a motor that draws 2-3 amps = 26-40 hours running time,just need to work out the speed to get a decent distance.

http://www.modelboatmayhem.co.uk/forum/index.php/topic,38347.0.html

Hi there, if you have a look at All nigh in's post number 13 - it states Guinness Book of Records' rules - about battery amperage - not to exceed 32 amps. So that snookers the 80 amp battery, that is if you want to stick to the Guinness Book of Records - anyway have you seen the physical size/weight of a 12 volt 80 amp battery.  (What size model are you putting this into).

If you really wish to challenge the grey matter - how about a self-navigating model - which would say cross The Firth of Forth from say Lower Largo to Cockenzie Port Seton.   Unaided with no  radio control so it just steers itself in one go - with possibly, say 2 people following in a rescue boat.

john